Part I: Single sized, pure arylene ether macrocycles ranging from 30 to 60 atom ring sizes were synthesized in good yields (up to 83%) by the two component method under high dilution conditions. These macrocycles have unsymmetric structures containing sulfone/ketone or sulfone/phosphine oxide functional groups and have relatively low melting points. The melt ROP of the single sized macrocycles to form poly(arylene ether)s exhibits two stage characteristics: the first stage is very fast, driven by the large entropy difference between cyclics and linears; the second stage is very slow and is diffusion controlled due to the high viscosity created in the first stage reaction. The latter stage leads to incomplete polymerization at the low initiator concentrations (1-3 mol%). At high initiator concentrations (5-7 mol%), 100% conversion is reached due to improved initiator distribution in macrocycles; however, this reduces molecular weights of the polymers. The molecular weight is found to build up very rapidly, independent of conversion, reaction time and type of initiator. The ROP is initiated by CsF and alkali phenoxides. The efficiency of the alkali counterion is generally in the order of Cs+>K+>Na+, while a phenoxide initiator is more efficient than a fluoride initiator. It is also found that the Cs counterion leads to highest degree of crosslinking. The ROP of cyclic oligomeric mixtures is also reported for comparison; the study shows that the molecular weight depends on time and conversion, and that the conversion is sensitive to the content of linear impurities and the average ring size of cyclic mixtures. Part II: Polyrotaxanes are novel polymeric materials comprised of linear polymer molecules and threaded macrocycles with no covalent bond between the two components. With potential movements of the cyclic component and judicious combinations of the two components of different properties, these materials have brought interesting changes of physical properties, such as morphology, crystallinity, solubility, viscosity, etc. In this part of the dissertation, a new family of polyrotaxanes with poly(arylene ether)s as backbones and crown ethers as cyclic components are described. These include linear poly(arylene ether) based polyrotaxanes and hyperbranched poly(ether ether ketone) based polyrotaxanes; both are synthesized via aromatic nucleophilic substitution reactions. Preliminary studies show that these polymers exhibit great enhancement of solubility. The polymers form emulsions in water and methanol which are normally non-solvents for the poly(arylene ether) backbones. In some cases, they are even soluble in water to form a clear solution. The attempted syntheses of polyrotaxanes using aromatic macrocycles described in Part I was not successful, with no indication of threading. / Ph. D.

Novel, highly functional rod-like copolymers have been synthesized by alternating copolymerization of N, N, Nâ , Nâ -tetraalkyl-4, 4â -diaminostilbenes (TDAS) with maleic anhydride. Dynamic light scattering, 2H solid state NMR and persistence length measurement reveal high chain rigidity of the polymer backbone. Double quantum heteronuclear local field solid state NMR spectroscopy (2Q-HLF Solid State NMR) has been employed to investigate the chain structure of ¹³C labelled copolymer. The torsional angle of the H-13C-13C-H part of the anhydride ring was zero degrees, indicating an all cis configuration of the H-13C-13C-H moiety of the anhydride ring. Rod-coil block copolymers containing rigid polyampholyte blocks were designed and synthesized by addition-fragmentation chain transfer (RAFT) copolymerization. The rigid polyampholytes blocks were formed by hydrolysis of alternating copolymers and the flexible coil block consists of poly(oligo(ethylene glycol) methacrylate). The rod-coil block copolymers form polyion complex (PIC) aggregates even when the polyampholyte blocks are charge imbalanced. The aggregates did not dissociate upon the addition of high concentrations of NaCl unlike the dissociation of flexible polyampholytes in NaCl solution. These unique solution properties are induced by 'like-charge attractions' of the rigid polyampholytic alternating copolymer chains. An example, of what is birefringent to be a novel class of material, has been prepared which enables the control of the birefringence of a polymer film by controlling the rotation of aromatic groups pendant to the polymer backbone. A linear rigid bisphenol monomer, 4,4′-dihydroxyterphenyl (DHTP), has been incorporated into poly(aryl ether sulfone)s (PAES) in a study to impart crystallization to these amorphous polymers. Three bisphenols, 4, 4′-isopropylidenediphenol, 4, 4′-(hexafluoroisopropylidene)diphenol and 4,4′-dihydroxybiphenyl have been copolymerized with DHTP and dichlorodiphenylsulfone. Only the segmented polysulfone containing 50% BP and 50% DHTP was semi-crystalline. This PAES had a melting temperature (Tm) 320°C in the first heating cycle of a DSC measurement and the presence of crystallites was confirmed by wide angle X-ray diffraction (WAXS). / Ph. D.

No description available.

Certaines applications (notamment dans l'aéronautique) demandent des polymères thermostables semi-cristallins avec des résistances et des températures de fonctionnement de plus en plus élevées (Tg supérieures à 170°C) tout en conservant de bonnes propriétés de mise en œuvre (Tf ne dépassant pas 350°C) aptes aux procédés industriels. Ce projet de thèse porte sur la synthèse et la caractérisation de nouveaux polymères hautes performances de type poly(aryl éther cétone amide)s à partir d'un monomère de type EKKE aux extrémités acide carboxylique. Ainsi, trois voies de synthèse des amides par condensation ont été étudiées : entre les acides carboxyliques et les isocyanates, entre les chlorures d'acyle et les amines, et entre les acides carboxyliques et les amines par phosphorylation. La comparaison des propriétés thermiques et leurs corrélations avec les structures chimiques des poly(aryl éther cétone amide)s aromatiques et semi-aromatiques obtenus sont particulièrement détaillées. / Some demanding applications (especially in aerospace) require more and more semi-crystalline thermostable polymers with high temperature resistance and durability (Tg above 170 °C) while maintaining good processing properties (Tm not exceeding 350°C) suitable for industrial manufacturing.This work deals with the synthesis and characterization of new high performance poly(aryl ether ketone amide)s polymers from an EKKE monomer with carboxylic acid extremities. Thus, three amide condensation synthetic routes were studied: between carboxylic acids and isocyanates, between acyl chlorides and amines, and between carboxylic acids and amines by phosphorylation. The thermal properties and their correlation with the chemical structures of the obtained aromatic and semi-aromatic poly(aryl ether ketone amide)s are compared and especially detailed.